| Phosphorus is one of a large number of nutrients which are essential to plant growth and development and application of phosphorate fertilizer is one of important measures to act high and stable yield of crops. Rock phosphate is a non-renewable resources and plays an important role in the national economy but it has been classified as one of the ten minerals that can not meet the future needs of national economic development by China Administrate of Land and Natural Resources. Although China's rock phosphate reserves largest in the world, but many of them can not be processed into water-soluble fertilizer such as superphosphate or ammonium phosphate using current techniques due to their low grade ore or the complexity of accompanied other minerals. A large number of water-soluble phosphate fertilizer application on farmland can be easily lost with draining water and easily leads to eutrophication of rivers and lakes. Ultrafine rock phosphate is a new type of fertilizer with simple processing of no use of sulfuric acid and makes full use of the advantages of phosphate rock resources but don't easily pollute the environment.In this study, the effects of the fineness and fermentation mixed with manure of rock phosphate powders on phosphorus release characteristics of chemical activation and on the growth, development and nutrient uptake of winter wheat and soil fertility were explored by the methods of laboratory analysis, pot experiments and plot experiments. The main results are as follows:1. Ultrafination of rock phosphate powder reduces its size, increases its surface area and content of citrate acid soluble phosphorus and accelerates the phosphorus release in the citric acid solution.The particle diameter of PR2, PR3 are respectively 4.9 times and 10.3 times of the common phosphate rock PR1 and are respectively 4.8 times and 10.2 times of the surface area of PR1. The citrate acid soluble phosphorus content of the former three extractions all have PR3> PR2> PR1 by successive extraction of 2% citric acid, and the differences between treatments were at significant levels (P<0.05).For the first time the concentrations of calcium, magnesium in the extraction are both PR3>PR2>PR1.2. Phosphorite powder ultra refined treatment promoted the growth and development of wheat plants and made the promotion of wheat absorption of P and and other nutrients such as N, K, Mg, Zn, Mn. Increasing the fineness of rock phosphate improves tillers and ears of wheat, plant height and chlorophyll content of cell processing plants and thus increased aboveground biomass of wheat and economic output. For the first, ultrafineness of rock phosphate powder promoted wheat plants on pot and plot absorb phosphorus and so increased phosphorus content and phosphorus uptake of the shoot of wheat in the growth periods. Second, the absorption of phosphorus further promote the wheat the uptake of other elements such as N, K, Mg, Zn, Mn. Applying superfine rock phosphate powder increased the uptake and content of nutrients of wheat shoot at different levels. (especially in the the middle and latter growth stages of wheats)3. Application of ultra-fine rock phosphate powder is conducive to maintaining and improving available phosphorus of soil. Application of rock phosphate powders increased soil Olsen-P content in the growth period of wheat plants; with the facilities to increase the fineness of rock phosphate, soil Olsen-P content increased. With the wheat growth and development, application of rock phosphate powder,the pot soil (0-10cm) Olsen-P content decreased slowly rock but the plot (0-10cm) Olsen-P content was increased. Application of rock phosphate powder improved active organic phosphorus content of the soil after harvest of wheat, and with the fineness of rock phosphate increased, the active organic phosphorus content of soils increased.4. The fermation mixed with manure increased the citrate acid soluble phosphorus content of the rock phosphate powder and the higher the fineness of rock phosphate powder was, the higher content of citrate acid soluble phosphate it had. Improving the proportion of manure and ultra-fine rock phosphate made the better the result. PR1, PR2, PR3 after fermentation mixed with cow dung had increased respectively than before fermentation by 0.4 times,0.6 times,0.6 times.The absolute citrate acid soluble phosphorus content of pure rock phosphate powder after fermentation is respectively 6.96%,9.36%,9.84%(by P2O5%) and Citrus medica dissolution rate reached 24.0%,32.3%,34%.The equivalent pure citrate acid soluble phosphorus contents of PR3 in fermentation products of whose weight ratio between manure and ultra-fine rock phosphate were 1:1,2:1 and 4:1,were 7.89%,9.84%, 10.66% respectively.5. Application of ultra-fine rock phosphate powder processing fermentation increased the growth and nutrient uptake of wheat and improved the available phosphorus and active organic phosphorus of the soils compared with before fermentation. And the finer the rock phosphate powder was, the better the result. With the ratio of manure increased, the better effect of the fermented ultra-fine rock phosphate powder got.
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